California's 16-year-old affirmative action ban is lodged more firmly than ever in state law after the U.S. Supreme Court on Tuesday shut off further court challenges in states that have enacted such bans.

By upholding a Michigan law nearly identical to California's, the ruling left only a legislative -- or ballot initiative -- route for allowing racial and gender preferences in public college admissions, contracts and hiring.

But those paths, too, are now littered with obstacles, as Democratic lawmakers discovered when a backlash from Chinese-American families last month scuttled legislation to let voters again consider the issue.

"I'm a very happy camper," said Ward Connerly, a former UC regent and architect of the California and Michigan laws.

Despite the setbacks, proponents of affirmative action say they're going to keep working toward giving minorities a boost in schools and jobs, and the author of California's most recent ill-fated legislation to overturn the state's ban says he hasn't given up.

"Yes, I'm going to hopefully bring it back," said Sen. Ed Hernandez, D-West Covina, who wrote -- and then was forced to withdraw -- Constitutional Amendment 5. "Quite a few colleagues have been very outspoken and said they want me to move forward."

But the Michigan case had major implications for California, where Proposition 209 -- approved by voters in 1996 -- has forbidden consideration of race and gender in university admissions and financial aid, contracting and other public programs throughout the state. Legal challenges to Proposition 209 failed, and its critics considered the Supreme Court case out of Michigan the last, best chance to revive a challenge in the courts.

Some say the ruling, combined with the political backlash in California, could end the debate.

"Prop. 209 is here to stay, and I don't think we're going to hear a lot about reforming it in the near future," predicted Terry Christensen, a political-science professor emeritus at San Jose State.

Asian-Americans voted against California's ban in 1996, but restoring race-conscious admissions in the increasingly competitive UC system struck a nerve with Chinese-Americans worried it would affect their children, who now have the highest admission rates.

Arguing that bans such as Michigan's particularly damage states with diverse populations, California, five other states and the District of Columbia joined civil rights groups in asking the Supreme Court to invalidate Michigan's Proposal 2, enacted in 2006. The University of California also opposed the law in the high court, noting that Prop. 209 dramatically reduced the admission rates for Latino, black and Native American students.

At Cal, the freshman admission rates for those three groups plunged by more than 50 percent between 1997 and 1998, the year the ban took effect -- from 45 percent to 20 percent. The proportion of black freshmen fell by half, to 3.4 percent of the class.

The Supreme Court, although splintered in its legal reasoning, determined that voters had a right to enact Michigan's law in 2006 and to choose to outlaw race and gender preferences. The majority decision, written by Justice Anthony Kennedy, was based on a states' rights argument, steering clear of whether Michigan's law violated the constitutional rights of minorities there.

"This case is not about the constitutionality, or the merits, of race-conscious admissions policies in higher education," Kennedy wrote.

The Michigan case was the latest to test the U.S. Supreme Court's evolving stance on affirmative action, dating back to its 2003 ruling upholding a narrowly crafted program allowing the consideration of race and gender at the University of Michigan's law school. The Supreme Court last year ordered the lower courts to take another look at the University of Texas' affirmative action guidelines, establishing tougher standards for permitting race and gender preferences in a public program.

In Tuesday's ruling, Justice Stephen Breyer agreed only with the result, while Justices Antonin Scalia and Clarence Thomas would have gone further, saying Michigan's approach to affirmative action is constitutional. Justices Sonia Sotomayor and Ruth Bader Ginsburg dissented. Justice Elena Kagan did not participate in the case.

Legal experts had predicted that the conservative Supreme Court was likely to leave intact laws such as Michigan's and California's. They also point to the latest admissions numbers from the statewide University of California, which show Latinos gaining ground. The largest ethnic group in UC's in-state applicant pool, Latinos made up nearly 29 percent of admitted students this year, the second largest group after Asian-Americans, who made up 36 percent. The proportion of white students dropped slightly to just under 27 percent.